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        <a href="windenergytk-module.html">Package&nbsp;windenergytk</a> ::
        Module&nbsp;analysis
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<h1 class="epydoc">Source Code for <a href="windenergytk.analysis-module.html">Module windenergytk.analysis</a></h1>
<pre class="py-src">
<a name="L1"></a><tt class="py-lineno">  1</tt>  <tt class="py-line"><tt class="py-comment">#!/usr/bin/env python</tt> </tt>
<a name="L2"></a><tt class="py-lineno">  2</tt>  <tt class="py-line"> </tt>
<a name="L3"></a><tt class="py-lineno">  3</tt>  <tt class="py-line"><tt class="py-comment">################################################################################</tt> </tt>
<a name="L4"></a><tt class="py-lineno">  4</tt>  <tt class="py-line"><tt class="py-comment"># analysis.py                                                                  #</tt> </tt>
<a name="L5"></a><tt class="py-lineno">  5</tt>  <tt class="py-line"><tt class="py-comment">#                                                                              #</tt> </tt>
<a name="L6"></a><tt class="py-lineno">  6</tt>  <tt class="py-line"><tt class="py-comment"># Part of UMass Amherst's Wind Energy Engineering Toolbox of Mini-Codes        #</tt> </tt>
<a name="L7"></a><tt class="py-lineno">  7</tt>  <tt class="py-line"><tt class="py-comment">#                   (or Mini-Codes for short)                                  #</tt> </tt>
<a name="L8"></a><tt class="py-lineno">  8</tt>  <tt class="py-line"><tt class="py-comment">#                                                                              #</tt> </tt>
<a name="L9"></a><tt class="py-lineno">  9</tt>  <tt class="py-line"><tt class="py-comment"># Python code by Alec Koumjian  -   akoumjian@gmail.com                        #</tt> </tt>
<a name="L10"></a><tt class="py-lineno"> 10</tt>  <tt class="py-line"><tt class="py-comment">#                                                                              #</tt> </tt>
<a name="L11"></a><tt class="py-lineno"> 11</tt>  <tt class="py-line"><tt class="py-comment"># This code adapted from the original Visual Basic code at                     #</tt> </tt>
<a name="L12"></a><tt class="py-lineno"> 12</tt>  <tt class="py-line"><tt class="py-comment"># http://www.ceere.org/rerl/projects/software/mini-code-overview.html          #</tt> </tt>
<a name="L13"></a><tt class="py-lineno"> 13</tt>  <tt class="py-line"><tt class="py-comment">#                                                                              #</tt> </tt>
<a name="L14"></a><tt class="py-lineno"> 14</tt>  <tt class="py-line"><tt class="py-comment"># These tools can be used in conjunction with the textbook                     #</tt> </tt>
<a name="L15"></a><tt class="py-lineno"> 15</tt>  <tt class="py-line"><tt class="py-comment"># "Wind Energy Explained" by J.F. Manwell, J.G. McGowan and A.L. Rogers        #</tt> </tt>
<a name="L16"></a><tt class="py-lineno"> 16</tt>  <tt class="py-line"><tt class="py-comment"># http://www.ceere.org/rerl/rerl_windenergytext.html                           #</tt> </tt>
<a name="L17"></a><tt class="py-lineno"> 17</tt>  <tt class="py-line"><tt class="py-comment">#                                                                              #</tt> </tt>
<a name="L18"></a><tt class="py-lineno"> 18</tt>  <tt class="py-line"><tt class="py-comment">################################################################################</tt> </tt>
<a name="L19"></a><tt class="py-lineno"> 19</tt>  <tt class="py-line"><tt class="py-comment">#   Copyright 2009 Alec Koumjian                                               #</tt> </tt>
<a name="L20"></a><tt class="py-lineno"> 20</tt>  <tt class="py-line"><tt class="py-comment">#                                                                              #</tt> </tt>
<a name="L21"></a><tt class="py-lineno"> 21</tt>  <tt class="py-line"><tt class="py-comment">#   This program is free software: you can redistribute it and/or modify       #</tt> </tt>
<a name="L22"></a><tt class="py-lineno"> 22</tt>  <tt class="py-line"><tt class="py-comment">#   it under the terms of the GNU General Public License as published by       #</tt> </tt>
<a name="L23"></a><tt class="py-lineno"> 23</tt>  <tt class="py-line"><tt class="py-comment">#   the Free Software Foundation, either version 3 of the License, or          #</tt> </tt>
<a name="L24"></a><tt class="py-lineno"> 24</tt>  <tt class="py-line"><tt class="py-comment">#   (at your option) any later version.                                        #</tt> </tt>
<a name="L25"></a><tt class="py-lineno"> 25</tt>  <tt class="py-line"><tt class="py-comment">#                                                                              #</tt> </tt>
<a name="L26"></a><tt class="py-lineno"> 26</tt>  <tt class="py-line"><tt class="py-comment">#    This program is distributed in the hope that it will be useful,           #</tt> </tt>
<a name="L27"></a><tt class="py-lineno"> 27</tt>  <tt class="py-line"><tt class="py-comment">#    but WITHOUT ANY WARRANTY; without even the implied warranty of            #</tt> </tt>
<a name="L28"></a><tt class="py-lineno"> 28</tt>  <tt class="py-line"><tt class="py-comment">#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             #</tt> </tt>
<a name="L29"></a><tt class="py-lineno"> 29</tt>  <tt class="py-line"><tt class="py-comment">#    GNU General Public License for more details.                              #</tt> </tt>
<a name="L30"></a><tt class="py-lineno"> 30</tt>  <tt class="py-line"><tt class="py-comment">#                                                                              #</tt> </tt>
<a name="L31"></a><tt class="py-lineno"> 31</tt>  <tt class="py-line"><tt class="py-comment">#    You should have received a copy of the GNU General Public License         #</tt> </tt>
<a name="L32"></a><tt class="py-lineno"> 32</tt>  <tt class="py-line"><tt class="py-comment">#    along with this program.  If not, see &lt;http://www.gnu.org/licenses/&gt;.     #</tt> </tt>
<a name="L33"></a><tt class="py-lineno"> 33</tt>  <tt class="py-line"><tt class="py-comment">################################################################################</tt> </tt>
<a name="L34"></a><tt class="py-lineno"> 34</tt>  <tt class="py-line"> </tt>
<a name="L35"></a><tt class="py-lineno"> 35</tt>  <tt class="py-line"> </tt>
<a name="L36"></a><tt class="py-lineno"> 36</tt>  <tt class="py-line"> </tt>
<a name="L37"></a><tt class="py-lineno"> 37</tt>  <tt class="py-line"> </tt>
<a name="L38"></a><tt class="py-lineno"> 38</tt>  <tt class="py-line"><tt class="py-keyword">from</tt> <tt class="py-name">numpy</tt> <tt class="py-keyword">import</tt> <tt class="py-name">histogram</tt> </tt>
<a name="L39"></a><tt class="py-lineno"> 39</tt>  <tt class="py-line"><tt class="py-keyword">from</tt> <tt class="py-name">numpy</tt> <tt class="py-keyword">import</tt> <tt class="py-name">mean</tt> <tt class="py-keyword">as</tt> <tt class="py-name">npmean</tt> </tt>
<a name="L40"></a><tt class="py-lineno"> 40</tt>  <tt class="py-line"><tt class="py-keyword">import</tt> <tt class="py-name">scikits</tt><tt class="py-op">.</tt><tt class="py-name">timeseries</tt> <tt class="py-keyword">as</tt> <tt class="py-name">ts</tt> </tt>
<a name="L41"></a><tt class="py-lineno"> 41</tt>  <tt class="py-line"><tt class="py-keyword">from</tt> <tt class="py-name">scipy</tt><tt class="py-op">.</tt><tt class="py-name">special</tt> <tt class="py-keyword">import</tt> <tt class="py-name">gamma</tt> </tt>
<a name="L42"></a><tt class="py-lineno"> 42</tt>  <tt class="py-line"><tt class="py-keyword">from</tt> <tt class="py-name">matplotlib</tt><tt class="py-op">.</tt><tt class="py-name">pyplot</tt> <tt class="py-keyword">import</tt> <tt class="py-name">psd</tt> </tt>
<a name="L43"></a><tt class="py-lineno"> 43</tt>  <tt class="py-line"> </tt>
<a name="L44"></a><tt class="py-lineno"> 44</tt>  <tt class="py-line"> </tt>
<a name="L45"></a><tt class="py-lineno"> 45</tt>  <tt class="py-line"><tt class="py-comment"># Core Functions #####################################################</tt> </tt>
<a name="L46"></a><tt class="py-lineno"> 46</tt>  <tt class="py-line"><tt class="py-comment">#      Statistics</tt> </tt>
<a name="L47"></a><tt class="py-lineno"> 47</tt>  <tt class="py-line"><tt class="py-comment">#      Histogram </tt> </tt>
<a name="L48"></a><tt class="py-lineno"> 48</tt>  <tt class="py-line"><tt class="py-comment">#      Weibull parameters </tt> </tt>
<a name="L49"></a><tt class="py-lineno"> 49</tt>  <tt class="py-line"><tt class="py-comment">#      Autocorrelation</tt> </tt>
<a name="L50"></a><tt class="py-lineno"> 50</tt>  <tt class="py-line"><tt class="py-comment">#      Crosscorrelation </tt> </tt>
<a name="L51"></a><tt class="py-lineno"> 51</tt>  <tt class="py-line"><tt class="py-comment">#      Block Average</tt> </tt>
<a name="L52"></a><tt class="py-lineno"> 52</tt>  <tt class="py-line"><tt class="py-comment">#      Power Spectral Density</tt> </tt>
<a name="L53"></a><tt class="py-lineno"> 53</tt>  <tt class="py-line"> </tt>
<a name="get_statistics"></a><div id="get_statistics-def"><a name="L54"></a><tt class="py-lineno"> 54</tt> <a class="py-toggle" href="#" id="get_statistics-toggle" onclick="return toggle('get_statistics');">-</a><tt class="py-line"><tt class="py-keyword">def</tt> <a class="py-def-name" href="windenergytk.analysis-module.html#get_statistics">get_statistics</a><tt class="py-op">(</tt><tt class="py-param">timeseries</tt><tt class="py-op">,</tt> <tt class="py-param">output</tt><tt class="py-op">=</tt><tt class="py-string">'dictionary'</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="get_statistics-collapsed" style="display:none;" pad="+++" indent="++++"></div><div id="get_statistics-expanded"><a name="L55"></a><tt class="py-lineno"> 55</tt>  <tt class="py-line">    <tt class="py-docstring">"""</tt> </tt>
<a name="L56"></a><tt class="py-lineno"> 56</tt>  <tt class="py-line"><tt class="py-docstring">    Collects statistics from a timeseries object.</tt> </tt>
<a name="L57"></a><tt class="py-lineno"> 57</tt>  <tt class="py-line"><tt class="py-docstring">    </tt> </tt>
<a name="L58"></a><tt class="py-lineno"> 58</tt>  <tt class="py-line"><tt class="py-docstring">    Input: A timeseries object, output format ('dictionary' or 'list')</tt> </tt>
<a name="L59"></a><tt class="py-lineno"> 59</tt>  <tt class="py-line"><tt class="py-docstring">    Output: Dictionary or array of mean, stdev, max, min, size</tt> </tt>
<a name="L60"></a><tt class="py-lineno"> 60</tt>  <tt class="py-line"><tt class="py-docstring">    """</tt> </tt>
<a name="L61"></a><tt class="py-lineno"> 61</tt>  <tt class="py-line">    <tt class="py-name">stat_names</tt> <tt class="py-op">=</tt> <tt class="py-op">[</tt><tt class="py-string">'mean'</tt><tt class="py-op">,</tt> <tt class="py-string">'std'</tt><tt class="py-op">,</tt> <tt class="py-string">'max'</tt><tt class="py-op">,</tt> <tt class="py-string">'min'</tt><tt class="py-op">,</tt> <tt class="py-string">'size'</tt><tt class="py-op">]</tt> </tt>
<a name="L62"></a><tt class="py-lineno"> 62</tt>  <tt class="py-line">    <tt class="py-name">stat_values</tt> <tt class="py-op">=</tt> <tt class="py-op">[</tt><tt class="py-name">timeseries</tt><tt class="py-op">.</tt><tt class="py-name">mean</tt><tt class="py-op">(</tt><tt class="py-op">)</tt><tt class="py-op">,</tt> <tt class="py-name">timeseries</tt><tt class="py-op">.</tt><tt class="py-name">std</tt><tt class="py-op">(</tt><tt class="py-op">)</tt><tt class="py-op">,</tt> </tt>
<a name="L63"></a><tt class="py-lineno"> 63</tt>  <tt class="py-line">    <tt class="py-name">timeseries</tt><tt class="py-op">.</tt><tt class="py-name">max</tt><tt class="py-op">(</tt><tt class="py-op">)</tt><tt class="py-op">,</tt> <tt class="py-name">timeseries</tt><tt class="py-op">.</tt><tt class="py-name">min</tt><tt class="py-op">(</tt><tt class="py-op">)</tt><tt class="py-op">,</tt><tt class="py-name">timeseries</tt><tt class="py-op">.</tt><tt class="py-name">size</tt><tt class="py-op">]</tt> </tt>
<a name="L64"></a><tt class="py-lineno"> 64</tt>  <tt class="py-line">     </tt>
<a name="L65"></a><tt class="py-lineno"> 65</tt>  <tt class="py-line">    <tt class="py-keyword">if</tt> <tt class="py-name">output</tt> <tt class="py-op">==</tt> <tt class="py-string">'list'</tt><tt class="py-op">:</tt> </tt>
<a name="L66"></a><tt class="py-lineno"> 66</tt>  <tt class="py-line">        <tt class="py-keyword">return</tt> <tt class="py-name">stat_values</tt> </tt>
<a name="L67"></a><tt class="py-lineno"> 67</tt>  <tt class="py-line">    <tt class="py-keyword">else</tt><tt class="py-op">:</tt> </tt>
<a name="L68"></a><tt class="py-lineno"> 68</tt>  <tt class="py-line">        <tt class="py-name">tsdict</tt> <tt class="py-op">=</tt> <tt class="py-op">{</tt><tt class="py-op">}</tt> </tt>
<a name="L69"></a><tt class="py-lineno"> 69</tt>  <tt class="py-line">        <tt class="py-keyword">for</tt> <tt class="py-name">index</tt> <tt class="py-keyword">in</tt> <tt class="py-name">range</tt><tt class="py-op">(</tt><tt class="py-number">5</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
<a name="L70"></a><tt class="py-lineno"> 70</tt>  <tt class="py-line">            <tt class="py-name">tsdict</tt><tt class="py-op">[</tt><tt class="py-name">stat_names</tt><tt class="py-op">[</tt><tt class="py-name">index</tt><tt class="py-op">]</tt><tt class="py-op">]</tt> <tt class="py-op">=</tt> <tt class="py-name">stat_values</tt><tt class="py-op">[</tt><tt class="py-name">index</tt><tt class="py-op">]</tt> </tt>
<a name="L71"></a><tt class="py-lineno"> 71</tt>  <tt class="py-line">        <tt class="py-keyword">return</tt> <tt class="py-name">tsdict</tt> </tt>
</div><a name="L72"></a><tt class="py-lineno"> 72</tt>  <tt class="py-line"> </tt>
<a name="get_histogram_data"></a><div id="get_histogram_data-def"><a name="L73"></a><tt class="py-lineno"> 73</tt> <a class="py-toggle" href="#" id="get_histogram_data-toggle" onclick="return toggle('get_histogram_data');">-</a><tt class="py-line"><tt class="py-keyword">def</tt> <a class="py-def-name" href="windenergytk.analysis-module.html#get_histogram_data">get_histogram_data</a><tt class="py-op">(</tt><tt class="py-param">timeseries</tt><tt class="py-op">,</tt> <tt class="py-param">bins</tt><tt class="py-op">=</tt><tt class="py-number">10</tt><tt class="py-op">,</tt> <tt class="py-param">normalized</tt><tt class="py-op">=</tt><tt class="py-name">True</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="get_histogram_data-collapsed" style="display:none;" pad="+++" indent="++++"></div><div id="get_histogram_data-expanded"><a name="L74"></a><tt class="py-lineno"> 74</tt>  <tt class="py-line">    <tt class="py-docstring">"""</tt> </tt>
<a name="L75"></a><tt class="py-lineno"> 75</tt>  <tt class="py-line"><tt class="py-docstring">    Returns histogram data of timeseries object</tt> </tt>
<a name="L76"></a><tt class="py-lineno"> 76</tt>  <tt class="py-line"><tt class="py-docstring">    Input: timeseries obj.</tt> </tt>
<a name="L77"></a><tt class="py-lineno"> 77</tt>  <tt class="py-line"><tt class="py-docstring">    Optional: No. of bins (default is 10), normalized (boolean)</tt> </tt>
<a name="L78"></a><tt class="py-lineno"> 78</tt>  <tt class="py-line"><tt class="py-docstring">    Output: Tuple (bins, histogram)</tt> </tt>
<a name="L79"></a><tt class="py-lineno"> 79</tt>  <tt class="py-line"><tt class="py-docstring">    """</tt> </tt>
<a name="L80"></a><tt class="py-lineno"> 80</tt>  <tt class="py-line">    <tt class="py-keyword">return</tt> <tt class="py-name">histogram</tt><tt class="py-op">(</tt><tt class="py-name">timeseries</tt><tt class="py-op">,</tt> <tt class="py-name">bins</tt><tt class="py-op">,</tt> <tt class="py-name">normed</tt><tt class="py-op">=</tt><tt class="py-name">normalized</tt><tt class="py-op">)</tt> </tt>
</div><a name="L81"></a><tt class="py-lineno"> 81</tt>  <tt class="py-line"> </tt>
<a name="get_weibull_params"></a><div id="get_weibull_params-def"><a name="L82"></a><tt class="py-lineno"> 82</tt> <a class="py-toggle" href="#" id="get_weibull_params-toggle" onclick="return toggle('get_weibull_params');">-</a><tt class="py-line"><tt class="py-keyword">def</tt> <a class="py-def-name" href="windenergytk.analysis-module.html#get_weibull_params">get_weibull_params</a><tt class="py-op">(</tt><tt class="py-param">mean</tt><tt class="py-op">,</tt> <tt class="py-param">stdev</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="get_weibull_params-collapsed" style="display:none;" pad="+++" indent="++++"></div><div id="get_weibull_params-expanded"><a name="L83"></a><tt class="py-lineno"> 83</tt>  <tt class="py-line">    <tt class="py-docstring">"""</tt> </tt>
<a name="L84"></a><tt class="py-lineno"> 84</tt>  <tt class="py-line"><tt class="py-docstring">    Returns Weibull parameters c and k.</tt> </tt>
<a name="L85"></a><tt class="py-lineno"> 85</tt>  <tt class="py-line"><tt class="py-docstring">    Input: mean, stdev</tt> </tt>
<a name="L86"></a><tt class="py-lineno"> 86</tt>  <tt class="py-line"><tt class="py-docstring">    Output: Weibull scale: c, shape: k</tt> </tt>
<a name="L87"></a><tt class="py-lineno"> 87</tt>  <tt class="py-line"><tt class="py-docstring">    Citation: Manwell 2000, chapter 2"""</tt> </tt>
<a name="L88"></a><tt class="py-lineno"> 88</tt>  <tt class="py-line">    <tt class="py-keyword">if</tt> <tt class="py-name">mean</tt> <tt class="py-op">&gt;</tt> <tt class="py-number">0</tt><tt class="py-op">:</tt> </tt>
<a name="L89"></a><tt class="py-lineno"> 89</tt>  <tt class="py-line">        <tt class="py-name">k</tt> <tt class="py-op">=</tt> <tt class="py-op">(</tt><tt class="py-name">stdev</tt> <tt class="py-op">/</tt> <tt class="py-name">mean</tt><tt class="py-op">)</tt><tt class="py-op">**</tt><tt class="py-op">-</tt><tt class="py-number">1.086</tt> </tt>
<a name="L90"></a><tt class="py-lineno"> 90</tt>  <tt class="py-line">        <tt class="py-name">c</tt> <tt class="py-op">=</tt>  <tt class="py-name">mean</tt> <tt class="py-op">/</tt> <tt class="py-name">gamma</tt><tt class="py-op">(</tt><tt class="py-number">1</tt> <tt class="py-op">+</tt> <tt class="py-number">1</tt> <tt class="py-op">/</tt> <tt class="py-name">k</tt><tt class="py-op">)</tt> </tt>
<a name="L91"></a><tt class="py-lineno"> 91</tt>  <tt class="py-line">    <tt class="py-keyword">else</tt><tt class="py-op">:</tt> </tt>
<a name="L92"></a><tt class="py-lineno"> 92</tt>  <tt class="py-line">        <tt class="py-name">k</tt><tt class="py-op">,</tt> <tt class="py-name">c</tt> <tt class="py-op">=</tt> <tt class="py-number">0</tt><tt class="py-op">,</tt> <tt class="py-number">0</tt> </tt>
<a name="L93"></a><tt class="py-lineno"> 93</tt>  <tt class="py-line">    <tt class="py-keyword">return</tt> <tt class="py-name">c</tt><tt class="py-op">,</tt> <tt class="py-name">k</tt> </tt>
</div><a name="L94"></a><tt class="py-lineno"> 94</tt>  <tt class="py-line"> </tt>
<a name="L95"></a><tt class="py-lineno"> 95</tt>  <tt class="py-line"> </tt>
<a name="crosscorrelate"></a><div id="crosscorrelate-def"><a name="L96"></a><tt class="py-lineno"> 96</tt> <a class="py-toggle" href="#" id="crosscorrelate-toggle" onclick="return toggle('crosscorrelate');">-</a><tt class="py-line"><tt class="py-keyword">def</tt> <a class="py-def-name" href="windenergytk.analysis-module.html#crosscorrelate">crosscorrelate</a><tt class="py-op">(</tt><tt class="py-param">timeseries1</tt><tt class="py-op">,</tt> <tt class="py-param">timeseries2</tt><tt class="py-op">,</tt> <tt class="py-param">max_lag_increment</tt><tt class="py-op">=</tt><tt class="py-name">False</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="crosscorrelate-collapsed" style="display:none;" pad="+++" indent="++++"></div><div id="crosscorrelate-expanded"><a name="L97"></a><tt class="py-lineno"> 97</tt>  <tt class="py-line">    <tt class="py-docstring">"""</tt> </tt>
<a name="L98"></a><tt class="py-lineno"> 98</tt>  <tt class="py-line"><tt class="py-docstring">    Returns crosscorrelation values at lag increments.</tt> </tt>
<a name="L99"></a><tt class="py-lineno"> 99</tt>  <tt class="py-line"><tt class="py-docstring">    Input: timeseries1, timeseries2</tt> </tt>
<a name="L100"></a><tt class="py-lineno">100</tt>  <tt class="py-line"><tt class="py-docstring">    Optional: max_lag_increment (int)</tt> </tt>
<a name="L101"></a><tt class="py-lineno">101</tt>  <tt class="py-line"><tt class="py-docstring">    Output: array of lags, array of correlation values</tt> </tt>
<a name="L102"></a><tt class="py-lineno">102</tt>  <tt class="py-line"><tt class="py-docstring">    """</tt> </tt>
<a name="L103"></a><tt class="py-lineno">103</tt>  <tt class="py-line">    <tt class="py-comment"># If no max_lag_increment, do it for the length of timeseries</tt> </tt>
<a name="L104"></a><tt class="py-lineno">104</tt>  <tt class="py-line">    <tt class="py-keyword">if</tt> <tt class="py-name">len</tt><tt class="py-op">(</tt><tt class="py-name">timeseries1</tt><tt class="py-op">)</tt> <tt class="py-op">&lt;</tt> <tt class="py-name">len</tt><tt class="py-op">(</tt><tt class="py-name">timeseries2</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
<a name="L105"></a><tt class="py-lineno">105</tt>  <tt class="py-line">        <tt class="py-name">smaller</tt> <tt class="py-op">=</tt> <tt class="py-name">timeseries1</tt> </tt>
<a name="L106"></a><tt class="py-lineno">106</tt>  <tt class="py-line">    <tt class="py-keyword">else</tt><tt class="py-op">:</tt> </tt>
<a name="L107"></a><tt class="py-lineno">107</tt>  <tt class="py-line">        <tt class="py-name">smaller</tt> <tt class="py-op">=</tt> <tt class="py-name">timeseries2</tt> </tt>
<a name="L108"></a><tt class="py-lineno">108</tt>  <tt class="py-line">    <tt class="py-keyword">if</tt> <tt class="py-keyword">not</tt> <tt class="py-name">max_lag_increment</tt><tt class="py-op">:</tt> </tt>
<a name="L109"></a><tt class="py-lineno">109</tt>  <tt class="py-line">        <tt class="py-name">max_lag_increment</tt><tt class="py-op">=</tt><tt class="py-name">len</tt><tt class="py-op">(</tt><tt class="py-name">smaller</tt><tt class="py-op">)</tt> </tt>
<a name="L110"></a><tt class="py-lineno">110</tt>  <tt class="py-line">         </tt>
<a name="L111"></a><tt class="py-lineno">111</tt>  <tt class="py-line">    <tt class="py-comment"># Create empty arrays, calculate means, std</tt> </tt>
<a name="L112"></a><tt class="py-lineno">112</tt>  <tt class="py-line">    <tt class="py-name">lag_values</tt> <tt class="py-op">=</tt> <tt class="py-op">[</tt><tt class="py-op">]</tt> </tt>
<a name="L113"></a><tt class="py-lineno">113</tt>  <tt class="py-line">    <tt class="py-name">crosscorrelation_values</tt> <tt class="py-op">=</tt> <tt class="py-op">[</tt><tt class="py-op">]</tt> </tt>
<a name="L114"></a><tt class="py-lineno">114</tt>  <tt class="py-line">    <tt class="py-name">difference_from_mean1</tt><tt class="py-op">,</tt> <tt class="py-name">difference_from_mean2</tt> <tt class="py-op">=</tt> <tt class="py-op">[</tt><tt class="py-op">]</tt><tt class="py-op">,</tt><tt class="py-op">[</tt><tt class="py-op">]</tt> </tt>
<a name="L115"></a><tt class="py-lineno">115</tt>  <tt class="py-line">    <tt class="py-name">mean1</tt><tt class="py-op">,</tt><tt class="py-name">mean2</tt> <tt class="py-op">=</tt> <tt class="py-name">timeseries1</tt><tt class="py-op">.</tt><tt class="py-name">mean</tt><tt class="py-op">(</tt><tt class="py-op">)</tt><tt class="py-op">,</tt><tt class="py-name">timeseries2</tt><tt class="py-op">.</tt><tt class="py-name">mean</tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L116"></a><tt class="py-lineno">116</tt>  <tt class="py-line">    <tt class="py-name">std1</tt><tt class="py-op">,</tt><tt class="py-name">std2</tt> <tt class="py-op">=</tt> <tt class="py-name">timeseries1</tt><tt class="py-op">.</tt><tt class="py-name">std</tt><tt class="py-op">(</tt><tt class="py-op">)</tt><tt class="py-op">,</tt><tt class="py-name">timeseries2</tt><tt class="py-op">.</tt><tt class="py-name">std</tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L117"></a><tt class="py-lineno">117</tt>  <tt class="py-line"> </tt>
<a name="L118"></a><tt class="py-lineno">118</tt>  <tt class="py-line">    <tt class="py-comment"># Subtract mean from timeseries values, save as new arrays</tt> </tt>
<a name="L119"></a><tt class="py-lineno">119</tt>  <tt class="py-line">    <tt class="py-keyword">for</tt> <tt class="py-name">array</tt><tt class="py-op">,</tt> <tt class="py-name">timeseries</tt><tt class="py-op">,</tt> <tt class="py-name">mean</tt> <tt class="py-keyword">in</tt> <tt class="py-op">[</tt><tt class="py-op">(</tt><tt class="py-name">difference_from_mean1</tt><tt class="py-op">,</tt> <tt class="py-name">timeseries1</tt><tt class="py-op">,</tt> <tt class="py-name">mean1</tt><tt class="py-op">)</tt><tt class="py-op">,</tt> </tt>
<a name="L120"></a><tt class="py-lineno">120</tt>  <tt class="py-line">                                    <tt class="py-op">(</tt><tt class="py-name">difference_from_mean2</tt><tt class="py-op">,</tt><tt class="py-name">timeseries2</tt><tt class="py-op">,</tt> <tt class="py-name">mean2</tt><tt class="py-op">)</tt><tt class="py-op">]</tt><tt class="py-op">:</tt> </tt>
<a name="L121"></a><tt class="py-lineno">121</tt>  <tt class="py-line">        <tt class="py-keyword">for</tt> <tt class="py-name">value</tt> <tt class="py-keyword">in</tt> <tt class="py-name">timeseries</tt><tt class="py-op">:</tt> </tt>
<a name="L122"></a><tt class="py-lineno">122</tt>  <tt class="py-line">            <tt class="py-name">array</tt><tt class="py-op">.</tt><tt class="py-name">append</tt><tt class="py-op">(</tt><tt class="py-name">value</tt><tt class="py-op">-</tt><tt class="py-name">mean</tt><tt class="py-op">)</tt> </tt>
<a name="L123"></a><tt class="py-lineno">123</tt>  <tt class="py-line"> </tt>
<a name="L124"></a><tt class="py-lineno">124</tt>  <tt class="py-line">    <tt class="py-comment"># Do comparison at different lags</tt> </tt>
<a name="L125"></a><tt class="py-lineno">125</tt>  <tt class="py-line">    <tt class="py-keyword">for</tt> <tt class="py-name">lag</tt> <tt class="py-keyword">in</tt> <tt class="py-name">range</tt><tt class="py-op">(</tt><tt class="py-number">0</tt><tt class="py-op">,</tt> <tt class="py-name">max_lag_increment</tt><tt class="py-op">+</tt><tt class="py-number">1</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
<a name="L126"></a><tt class="py-lineno">126</tt>  <tt class="py-line">        <tt class="py-name">mysum</tt> <tt class="py-op">=</tt> <tt class="py-number">0</tt> </tt>
<a name="L127"></a><tt class="py-lineno">127</tt>  <tt class="py-line">        <tt class="py-keyword">for</tt> <tt class="py-name">timestep</tt> <tt class="py-keyword">in</tt> <tt class="py-name">range</tt><tt class="py-op">(</tt><tt class="py-number">0</tt><tt class="py-op">,</tt><tt class="py-name">len</tt><tt class="py-op">(</tt><tt class="py-name">smaller</tt><tt class="py-op">)</tt><tt class="py-op">-</tt><tt class="py-name">lag</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
<a name="L128"></a><tt class="py-lineno">128</tt>  <tt class="py-line">            <tt class="py-name">mysum</tt> <tt class="py-op">+=</tt> <tt class="py-op">(</tt><tt class="py-name">difference_from_mean1</tt><tt class="py-op">[</tt><tt class="py-name">timestep</tt><tt class="py-op">]</tt> <tt class="py-op">*</tt> \ </tt>
<a name="L129"></a><tt class="py-lineno">129</tt>  <tt class="py-line">            <tt class="py-name">difference_from_mean2</tt><tt class="py-op">[</tt><tt class="py-name">timestep</tt><tt class="py-op">+</tt><tt class="py-name">lag</tt><tt class="py-op">]</tt><tt class="py-op">)</tt> </tt>
<a name="L130"></a><tt class="py-lineno">130</tt>  <tt class="py-line">            <tt class="py-name">normalized_value</tt> <tt class="py-op">=</tt> <tt class="py-name">mysum</tt> <tt class="py-op">/</tt> <tt class="py-op">(</tt><tt class="py-op">(</tt><tt class="py-name">std1</tt><tt class="py-op">*</tt><tt class="py-name">std2</tt><tt class="py-op">)</tt><tt class="py-op">*</tt><tt class="py-op">(</tt><tt class="py-name">len</tt><tt class="py-op">(</tt><tt class="py-name">smaller</tt><tt class="py-op">)</tt><tt class="py-op">-</tt><tt class="py-name">lag</tt><tt class="py-op">)</tt><tt class="py-op">)</tt> </tt>
<a name="L131"></a><tt class="py-lineno">131</tt>  <tt class="py-line">        <tt class="py-name">lag_values</tt><tt class="py-op">.</tt><tt class="py-name">append</tt><tt class="py-op">(</tt><tt class="py-name">lag</tt><tt class="py-op">)</tt> </tt>
<a name="L132"></a><tt class="py-lineno">132</tt>  <tt class="py-line">        <tt class="py-name">crosscorrelation_values</tt><tt class="py-op">.</tt><tt class="py-name">append</tt><tt class="py-op">(</tt><tt class="py-name">normalized_value</tt><tt class="py-op">)</tt> </tt>
<a name="L133"></a><tt class="py-lineno">133</tt>  <tt class="py-line">    <tt class="py-keyword">return</tt> <tt class="py-name">lag_values</tt><tt class="py-op">,</tt> <tt class="py-name">crosscorrelation_values</tt> </tt>
</div><a name="L134"></a><tt class="py-lineno">134</tt>  <tt class="py-line"> </tt>
<a name="autocorrelate"></a><div id="autocorrelate-def"><a name="L135"></a><tt class="py-lineno">135</tt> <a class="py-toggle" href="#" id="autocorrelate-toggle" onclick="return toggle('autocorrelate');">-</a><tt class="py-line"><tt class="py-keyword">def</tt> <a class="py-def-name" href="windenergytk.analysis-module.html#autocorrelate">autocorrelate</a><tt class="py-op">(</tt><tt class="py-param">timeseries</tt><tt class="py-op">,</tt> <tt class="py-param">max_lag_increment</tt><tt class="py-op">=</tt><tt class="py-name">False</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="autocorrelate-collapsed" style="display:none;" pad="+++" indent="++++"></div><div id="autocorrelate-expanded"><a name="L136"></a><tt class="py-lineno">136</tt>  <tt class="py-line">    <tt class="py-docstring">"""</tt> </tt>
<a name="L137"></a><tt class="py-lineno">137</tt>  <tt class="py-line"><tt class="py-docstring">    Returns autocorrelation values at lag increments.</tt> </tt>
<a name="L138"></a><tt class="py-lineno">138</tt>  <tt class="py-line"><tt class="py-docstring">    Input: a single timeseries object</tt> </tt>
<a name="L139"></a><tt class="py-lineno">139</tt>  <tt class="py-line"><tt class="py-docstring">    optional: max_lag_increment</tt> </tt>
<a name="L140"></a><tt class="py-lineno">140</tt>  <tt class="py-line"><tt class="py-docstring">    Output: Array of lags, Array of normalized autocorrelation values.</tt> </tt>
<a name="L141"></a><tt class="py-lineno">141</tt>  <tt class="py-line"><tt class="py-docstring">    """</tt> </tt>
<a name="L142"></a><tt class="py-lineno">142</tt>  <tt class="py-line">    <tt class="py-keyword">return</tt> <tt id="link-0" class="py-name" targets="Function windenergytk.analysis.crosscorrelate()=windenergytk.analysis-module.html#crosscorrelate"><a title="windenergytk.analysis.crosscorrelate" class="py-name" href="#" onclick="return doclink('link-0', 'crosscorrelate', 'link-0');">crosscorrelate</a></tt><tt class="py-op">(</tt><tt class="py-name">timeseries</tt><tt class="py-op">,</tt> <tt class="py-name">timeseries</tt><tt class="py-op">,</tt> <tt class="py-name">max_lag_increment</tt><tt class="py-op">)</tt> </tt>
</div><a name="L143"></a><tt class="py-lineno">143</tt>  <tt class="py-line"> </tt>
<a name="block_average"></a><div id="block_average-def"><a name="L144"></a><tt class="py-lineno">144</tt> <a class="py-toggle" href="#" id="block_average-toggle" onclick="return toggle('block_average');">-</a><tt class="py-line"><tt class="py-keyword">def</tt> <a class="py-def-name" href="windenergytk.analysis-module.html#block_average">block_average</a><tt class="py-op">(</tt><tt class="py-param">timeseries</tt><tt class="py-op">,</tt> <tt class="py-param">new_freq</tt><tt class="py-op">=</tt><tt class="py-string">''</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="block_average-collapsed" style="display:none;" pad="+++" indent="++++"></div><div id="block_average-expanded"><a name="L145"></a><tt class="py-lineno">145</tt>  <tt class="py-line">    <tt class="py-docstring">"""</tt> </tt>
<a name="L146"></a><tt class="py-lineno">146</tt>  <tt class="py-line"><tt class="py-docstring">    Reduce size of timeseries by taking averages of larger block size.</tt> </tt>
<a name="L147"></a><tt class="py-lineno">147</tt>  <tt class="py-line"><tt class="py-docstring">    Input: timeseries, new_freq (str) See scikits.timeseries doc</tt> </tt>
<a name="L148"></a><tt class="py-lineno">148</tt>  <tt class="py-line"><tt class="py-docstring">    Output: block averaged timeseries obj. in new frequency</tt> </tt>
<a name="L149"></a><tt class="py-lineno">149</tt>  <tt class="py-line"><tt class="py-docstring">    """</tt> </tt>
<a name="L150"></a><tt class="py-lineno">150</tt>  <tt class="py-line">    <tt class="py-comment"># Label timeseries data with new frequency</tt> </tt>
<a name="L151"></a><tt class="py-lineno">151</tt>  <tt class="py-line">    <tt class="py-comment"># ie: [5.5, 4.5] | [13-May-2009 11:40 13-May-2009 11:50] becomes</tt> </tt>
<a name="L152"></a><tt class="py-lineno">152</tt>  <tt class="py-line">    <tt class="py-comment">#     [5.5, 4.5] | [13-May-2009 13-May-2009]</tt> </tt>
<a name="L153"></a><tt class="py-lineno">153</tt>  <tt class="py-line">    <tt class="py-name">timeseries</tt> <tt class="py-op">=</tt> <tt class="py-name">timeseries</tt><tt class="py-op">.</tt><tt class="py-name">asfreq</tt><tt class="py-op">(</tt><tt class="py-name">new_freq</tt><tt class="py-op">)</tt> </tt>
<a name="L154"></a><tt class="py-lineno">154</tt>  <tt class="py-line"> </tt>
<a name="L155"></a><tt class="py-lineno">155</tt>  <tt class="py-line">    <tt class="py-comment"># Create empty arrays, set first block_time</tt> </tt>
<a name="L156"></a><tt class="py-lineno">156</tt>  <tt class="py-line">    <tt class="py-name">current_block_values</tt> <tt class="py-op">=</tt> <tt class="py-op">[</tt><tt class="py-op">]</tt> </tt>
<a name="L157"></a><tt class="py-lineno">157</tt>  <tt class="py-line">    <tt class="py-name">averages</tt> <tt class="py-op">=</tt> <tt class="py-op">[</tt><tt class="py-op">]</tt> </tt>
<a name="L158"></a><tt class="py-lineno">158</tt>  <tt class="py-line">    <tt class="py-name">timesteps</tt> <tt class="py-op">=</tt> <tt class="py-op">[</tt><tt class="py-op">]</tt> </tt>
<a name="L159"></a><tt class="py-lineno">159</tt>  <tt class="py-line">    <tt class="py-name">current_block_time</tt> <tt class="py-op">=</tt> <tt class="py-name">timeseries</tt><tt class="py-op">.</tt><tt class="py-name">dates</tt><tt class="py-op">[</tt><tt class="py-number">0</tt><tt class="py-op">]</tt> </tt>
<a name="L160"></a><tt class="py-lineno">160</tt>  <tt class="py-line"> </tt>
<a name="L161"></a><tt class="py-lineno">161</tt>  <tt class="py-line">    <tt class="py-comment"># For each index in timeseries, if the block of time has changed,</tt> </tt>
<a name="L162"></a><tt class="py-lineno">162</tt>  <tt class="py-line">    <tt class="py-comment"># average the previous block values.  Otherwise keep adding</tt> </tt>
<a name="L163"></a><tt class="py-lineno">163</tt>  <tt class="py-line">    <tt class="py-comment"># values to be averaged.</tt> </tt>
<a name="L164"></a><tt class="py-lineno">164</tt>  <tt class="py-line">    <tt class="py-keyword">for</tt> <tt class="py-name">index</tt> <tt class="py-keyword">in</tt> <tt class="py-name">range</tt><tt class="py-op">(</tt><tt class="py-number">0</tt><tt class="py-op">,</tt><tt class="py-name">len</tt><tt class="py-op">(</tt><tt class="py-name">timeseries</tt><tt class="py-op">)</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
<a name="L165"></a><tt class="py-lineno">165</tt>  <tt class="py-line">        <tt class="py-keyword">if</tt> <tt class="py-name">current_block_time</tt> <tt class="py-op">!=</tt> <tt class="py-name">timeseries</tt><tt class="py-op">.</tt><tt class="py-name">dates</tt><tt class="py-op">[</tt><tt class="py-name">index</tt><tt class="py-op">]</tt><tt class="py-op">:</tt> </tt>
<a name="L166"></a><tt class="py-lineno">166</tt>  <tt class="py-line">            <tt class="py-name">averages</tt><tt class="py-op">.</tt><tt class="py-name">append</tt><tt class="py-op">(</tt><tt class="py-name">npmean</tt><tt class="py-op">(</tt><tt class="py-name">current_block_values</tt><tt class="py-op">)</tt><tt class="py-op">)</tt> </tt>
<a name="L167"></a><tt class="py-lineno">167</tt>  <tt class="py-line">            <tt class="py-name">timesteps</tt><tt class="py-op">.</tt><tt class="py-name">append</tt><tt class="py-op">(</tt><tt class="py-name">current_block_time</tt><tt class="py-op">)</tt> </tt>
<a name="L168"></a><tt class="py-lineno">168</tt>  <tt class="py-line">            <tt class="py-name">current_block_values</tt> <tt class="py-op">=</tt> <tt class="py-op">[</tt><tt class="py-op">]</tt> </tt>
<a name="L169"></a><tt class="py-lineno">169</tt>  <tt class="py-line">            <tt class="py-name">current_block_time</tt> <tt class="py-op">=</tt> <tt class="py-name">timeseries</tt><tt class="py-op">.</tt><tt class="py-name">dates</tt><tt class="py-op">[</tt><tt class="py-name">index</tt><tt class="py-op">]</tt> </tt>
<a name="L170"></a><tt class="py-lineno">170</tt>  <tt class="py-line">        <tt class="py-name">current_block_values</tt><tt class="py-op">.</tt><tt class="py-name">append</tt><tt class="py-op">(</tt><tt class="py-name">timeseries</tt><tt class="py-op">[</tt><tt class="py-name">index</tt><tt class="py-op">]</tt><tt class="py-op">)</tt> </tt>
<a name="L171"></a><tt class="py-lineno">171</tt>  <tt class="py-line">    <tt class="py-comment"># Take average for last (or only) time block</tt> </tt>
<a name="L172"></a><tt class="py-lineno">172</tt>  <tt class="py-line">    <tt class="py-keyword">if</tt> <tt class="py-name">current_block_values</tt><tt class="py-op">:</tt> </tt>
<a name="L173"></a><tt class="py-lineno">173</tt>  <tt class="py-line">        <tt class="py-name">averages</tt><tt class="py-op">.</tt><tt class="py-name">append</tt><tt class="py-op">(</tt><tt class="py-name">npmean</tt><tt class="py-op">(</tt><tt class="py-name">current_block_values</tt><tt class="py-op">)</tt><tt class="py-op">)</tt> </tt>
<a name="L174"></a><tt class="py-lineno">174</tt>  <tt class="py-line">        <tt class="py-name">timesteps</tt><tt class="py-op">.</tt><tt class="py-name">append</tt><tt class="py-op">(</tt><tt class="py-name">current_block_time</tt><tt class="py-op">)</tt> </tt>
<a name="L175"></a><tt class="py-lineno">175</tt>  <tt class="py-line">         </tt>
<a name="L176"></a><tt class="py-lineno">176</tt>  <tt class="py-line"> </tt>
<a name="L177"></a><tt class="py-lineno">177</tt>  <tt class="py-line">    <tt class="py-comment"># Return new block averages and timesteps as timeseries object</tt> </tt>
<a name="L178"></a><tt class="py-lineno">178</tt>  <tt class="py-line">    <tt class="py-keyword">return</tt> <tt class="py-name">ts</tt><tt class="py-op">.</tt><tt class="py-name">time_series</tt><tt class="py-op">(</tt><tt class="py-name">averages</tt><tt class="py-op">,</tt><tt class="py-name">dates</tt><tt class="py-op">=</tt><tt class="py-name">timesteps</tt><tt class="py-op">)</tt> </tt>
</div><a name="L179"></a><tt class="py-lineno">179</tt>  <tt class="py-line"> </tt>
<a name="L180"></a><tt class="py-lineno">180</tt>  <tt class="py-line"> </tt>
<a name="power_spectral_density"></a><div id="power_spectral_density-def"><a name="L181"></a><tt class="py-lineno">181</tt> <a class="py-toggle" href="#" id="power_spectral_density-toggle" onclick="return toggle('power_spectral_density');">-</a><tt class="py-line"><tt class="py-keyword">def</tt> <a class="py-def-name" href="windenergytk.analysis-module.html#power_spectral_density">power_spectral_density</a><tt class="py-op">(</tt><tt class="py-param">data_array</tt><tt class="py-op">,</tt> <tt class="py-param">frequency</tt><tt class="py-op">,</tt> <tt class="py-param">window_method</tt><tt class="py-op">=</tt><tt class="py-name">False</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="power_spectral_density-collapsed" style="display:none;" pad="+++" indent="++++"></div><div id="power_spectral_density-expanded"><a name="L182"></a><tt class="py-lineno">182</tt>  <tt class="py-line">    <tt class="py-keyword">return</tt> <tt class="py-name">psd</tt><tt class="py-op">(</tt><tt class="py-name">data_array</tt><tt class="py-op">,</tt> <tt class="py-name">Fs</tt> <tt class="py-op">=</tt> <tt class="py-name">frequency</tt><tt class="py-op">)</tt> </tt>
</div><a name="L183"></a><tt class="py-lineno">183</tt>  <tt class="py-line"> </tt><script type="text/javascript">
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